An in vitro investigation on the cytotoxic and nuclear receptor transcriptional activity of the mycotoxins fumonisin B1 and beauvericin

At the receptor level, 0.001-10 μM BEA or FB1 did not induce any agonist responses in the RGAs. However at non-cytotoxic concentrations, an antagonistic effect was exhibited by FB1 on the androgen nuclear receptor transcriptional activity at 10 μM and BEA on the progestagen and glucocorticoid receptors at 1 μM. MTT analysis showed no decrease in cell viability at any concentration of FB1, whereas BEA showed a significant decrease in viability at 10 μM. HCA analysis confirmed that the reduction in the progestagen receptor transcriptional activity at 1 μM BEA was not due to pre-lethal toxicity. In addition, BEA (10 μM) induced significant toxicity in both the TM-Luc (progestagen responsive) and Caco-2 cells.